In recent years, diagnosis of coronary stenosis lesion has been made by both of “anatomical evaluation” of morphologically evaluating the presence or absence of the stenosis, the degree of the stenosis, and the like and “physiological evaluation” of objectively evaluating the presence or absence of myocardial ischemia, the degree of the myocardial ischemia, and the like. As physiological indicators to be used for the “physiological evaluation”, a fractional flow reserve (FFR), a coronary flow reserve (CFR), and the like, get attention. For example, the FFR is an indicator indicating the degree of myocardial ischemia caused by the coronary stenosis. The FFR is indicated by a ratio of a maximum coronary blood flow rate under the presence of the stenosis and a maximum coronary blood flow rate under the absence of the stenosis. For example, the CFR is an indicator indicating capability to increase the coronary blood flow rate in accordance with increase in oxygen demand on the myocardium. The CFR is indicated by a ratio of a coronary blood flow rate at rest and a coronary blood flow rate at maximum reactive hyperemia.
Conventionally, these physiological indicators are calculated by a predetermined measuring device. The measuring device, for example, has a pressure sensor-equipped guide wire (pressure wire) and measures an intracoronary pressure so as to calculate the FFR. Furthermore, for example, the measuring device has a guide wire (Doppler wire) mounted with an ultrasound probe on a front end thereof and measures a blood flow velocity of the coronary artery with the ultrasound probe so as to calculate the CFR.
Conventional examples are described in Japanese Translation of PCT Application Publication No. 2010-526556, Japanese Translation of PCT Application Publication No. 2004-528920, Japanese Translation of PCT Application Publication No. 2003-525067, and Japanese Laid-open Patent Publication No. 2011-156321.